feat: revamp CYMONIA marketing, SEO and repository structure

[SignalLayerLabs]

CYMONIA Marketing + Repository Revamp

Reposition CYMONIA around what the project has become: a live, persistent artificial civilization driven by autonomous AI Citizens inside a causal world.

Product positioning

• New product-led README
• Clear top-level message:
  100 Genesis Citizens. Zero prebuilt society. One causal world.
• Positioning around persistent artificial civilization, autonomous AI agents, artificial life, multi-agent systems and emergent behavior
• Live-world CTA above the fold
• Real Observer screenshot
• Product differentiation, architecture, FAQ, technical stack and contributor funnel

SEO

• Rewritten title and meta description
• Canonical URL
• Open Graph metadata
• Twitter large-image card
• JSON-LD WebSite + SoftwareApplication
• robots.txt
• sitemap.xml
• llms.txt
• Real CYMONIA Observer image replaces obsolete social preview

Repository cleanup

Documentation reorganized into:

• docs/architecture
• docs/design
• docs/observer
• docs/operations
• docs/reference
• docs/history
• docs/images

Removed obsolete presentation assets:

• site/cinematic-world.css
• site/assets/world-backdrop.png
• site/assets/world-buildings.png
• site/assets/world-citizens.png
• site/assets/world-terrain.png

Contributor experience

• Documentation hub
• Complete repository map
• Rewritten CONTRIBUTING guide
• Updated SECURITY policy
• CODEOWNERS
• Structured issue forms
• PR template centered on authority boundaries and evidence

Verification

• Marketing / SEO contract: 4/4 passed
• Sovereign suite: 112/112 passed
• Deterministic Genesis replay passed
• Package manifest passed
• Browser sovereign smoke passed
• Zero page errors
• git diff --check passed